Analysis of information sources in references of the Wikipedia article "Ανελίζε Μίχελ" in Greek language version.
When treatment by the family physician and various psychiatrists brought her no relief, the bishop of her diocese gave permission to two priests to carry out the ritual of exorcism.
It involved a German girl named Anneliese Michel, who was treated for seizures and given drugs over a period of five years before the Church finally authorized an exorcism; its investigation indicated she was possessed by, among others, Lucifer, Judas, Nero, Cain, and Hitler.
Michel's deeply devout, conservative Catholic community was convinced that she was possessed by the devil after they had seen her hostile reaction to holy communion during pilgrimage to patron saint San Damiano in Italy.